eLetters to:

ARTICLE: Keith J. Barrington, Dale Bull, and Neil N. Finer Randomized Trial of Nasal Synchronized Intermittent Mandatory Ventilation Compared With Continuous Positive Airway Pressure After Extubation of Very Low Birth Weight Infants Pediatrics 2001; 107: 638-641 [Abstract] [Full text] [PDF]

eLetters: Submit a response to this article

eLetters published:

Invasive, less invasive or noninvasive - it's not only a question of definition.

Yoram A Bental   (4 April 2001)

Response to Dr Bental

Keith J Barrington   (10 April 2001)

Untitled

Osama Ebesh   (24 May 2001)

Invasive, less invasive or noninvasive - it's not only a question of definition. 4 April 2001
Yoram A Bental, Director-NICU Sanz Medical Center, Laniado Hospital, Israel Send letter to journal: Re: Invasive, less invasive or noninvasive - it's not only a question of definition. yabental{at}tx.technion.ac.il Yoram A Bental	áñ"ã To the Editor, I read with great interest this excellent study. I have a few remarks/questions if I may: 1. I think we should be very careful in relating to nSIMV or nCPAP as “noninvasive ventilation” – it could be misleading. We all know these techniques have complications such as damage to the nasal septum, irritation of the nasal mucosa, pneumothoracies, PIE, BPD, feeding intolerance and GI perforation (and more). These complications have implications on long-term outcome so I suggest we use the term “less invasive” instead. 2. What was the mean airway pressure (MAP) in the nSIMV group? If it was higher in this group could this account for the different results? 3. According to your clinical impression was the statistical significance of p<.05 also clinically significant? 4. I totally agree with the author's belief that the use of these techniques will significantly reduce neonatal morbidity and that more research should be carried out. We have been using the bubble nCPAP technique for almost two years now and compared with historical data the results are better (numbers are small so statistical analysis is difficult). A comparison of bubble nCPAP with the techniques used in this study would probably be very interesting.
Response to Dr Bental 10 April 2001
Keith J Barrington, Neonatologist McGill University Send letter to journal: Re: Response to Dr Bental keith.barrington{at}mcgill.ca Keith J Barrington	Thank you for your comments. We referred to the methodology as "non- invasive" as it eliminates the need for an endotracheal tube, and nasal ventilation has often been referred to by that name in older patients. It is certainly true that this does not imply "without complications". As we state in the article the incidence of uncommon complications will require a much larger study and on-going surveillance. The mean airway pressure in either group is uncertain. The mean pressure in the ventilator circuit was higher in the nSIMV group, as both had a PEEP of 6 cmH2O, and the nSIMV group had additional positive pressure breaths. Therefore it is very likely that the mean airway pressure would have been slightly higher had it been possible to measure it. In some preliminary observations, the posterior pharyngeal pressures were independently measured during nSIMV with the ventilator set up described in the paper. This showed pressures in the posterior pharynx usually within 2 cmH2O of the ventilator circuit pressures, during all phases of ventilation. We of course discussed the ventilator settings to be used during the design phase of the study: should we match mean circuit pressures and thus have a lower PEEP in the nSIMV group, or match PEEP and thus have a higher mean pressure in the nSIMV group? Either approach could be criticized; and to answer the question of whether it is the positive pressure breaths or the slightly higher mean pressure that was the effective factor would have required 3 groups and the attendant difficulty in completing the study. It should be remembered that at a starting rate of 12 and a peak pressure goal of 12 cmH2O the increase in mean circuit pressure was minor, from 6 to about 6.5 cmH2O. The question of the clinical importance of the results will require more study. I hope that doesn’t sound like I am ducking the question; I do think that a reduction in serious apneas and in the incidence of serious hypercapnia may be important, but we have not shown that serious long term complications of prematurity have been affected. Does it matter if extubation is more likely to be successful? I would suggest that it only matters if other complications are not increased. There are many unanswered questions in neonatal intensive care; the most effective and least complicated way to support ventilation is certainly one issue that requires further study.
Untitled 24 May 2001
Osama Ebesh, Almana General Hospital, Alkhobar, Saudi Arabia Send letter to journal: Re: this article oebesh{at}hotmail.com Osama Ebesh	Dear Drs. Barrington, Bull, and Finer: I would like to congratulate you for prooving that nSIMV is really a good non invasive mode of weaning from mechanical ventilation in LBW infants. During my fellowship at North Shore University Hospital, Manhasset, NY; (1995-1998) we used this mode of ventilation at our unit very frequent after extubation sometimes, and sometimes as a manuever to avoid reintubation. It was really very succesfull. We usually used nSIMV of 20 rate and pressure of 20/5 (measured by occlusion of the nasal prongs) attached to Bear Cub Vetilator, and we used to wain by decreasing the rate by 5 as per arterial or capillay blood gas untill we reach a NCPAP (rate of 0), then to discontue this CPAP if the infant can tolerate that. We try this mode of ventilation to large preterm infants and full term but without imressive results. Some preterm infants recieced nSIMV as a mode of ventilation since birth and they did not need intubation at all. In that period no infant had significant side effect except some cases of gastric distetion and feeding intolerance. During that time I review the letreture and couln't find a supportive study to our work. I do not have any ststics about our work during that period but I can assure you that applying this mode was a good alternate to intubation and invasive mechanical ventilation. Your study will open the way to apply this mode of support as aa nonivasive way of ventilation